Abstract
The energy policy of the European member States is promoting high-efficiency cogeneration systems by means of the European directive 2012/27/EU. Particular facilitations have been implemented for the small-scale and micro-cogeneration units. Furthermore, the directive 2010/31/EU promotes the improvement of energy performance of buildings and use of energy from renewable sources for the building sector. In this scenario, systems based on gasification are considered a promising technological solution when dealing with biomass and small scale systems. In this paper, an integrated approach has been implemented to assess the energy performance of combined heat and power (CHP) systems based on biomass gasification and installed in residential blocks. The space-heating loads of the considered building configurations have been simulated by means of EnergyPlus. The heat load for domestic hot water demand has been calculated according to the average daily profiles suggested by the Italian and European technical standards. The efficiency of the whole CHP system has been evaluated supplementing the simulation of the gasification stage with the energy balance of the cogeneration set (i.e., internal combustion engine) and implementing the devel- oped routines in the Matlab-Simulink environment. The developed model has been used to evaluate the primary energy saving (PES) of the CHP system compared to a reference case of separate production of heat and power. Economic analyses are performed either with or without subsidizations for the generated electricity. The results highlight the capability of the integrated approach to estimate both energy and economic performances of CHP systems applied to the residential context. Furthermore, the importance of the generated heat valorisation and the proper system sizing have been discussed.